<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }

        form{
            width:500px;
            padding: 20px;
            border: 10px solid orange;
            border-radius: 10px;
            margin: 50px auto;
        }

        form > label {
            height:70px;
            position: relative;
            display:block;
        }

        form > label > span {
            height:20px;
            position: absolute;
            left:0;
            bottom: 10px;
            font-size: 30px;
            color:red;
        }

    </style>
</head>
<body>
    <div id="app">
        <div class="header">
            <p v-if="!flag">你好,<a href="#">请登录</a></p>
            <p v-if="flag">欢迎您<span>***<b>先生</b></span><a href="#">个人中心</a></p>
        </div>

    </div>
    <script src="./vue.global.js"></script>
    <script>
         const {createApp} = Vue;
        createApp({
            data(){
                return {
                    flag:true
                }
            }
        }).mount('#app')
    </script>
</body>
</html>